Carburetor



Feb. 11, 1930. LINGA 1,746,786

CARBURETOR Filed July 11, 1925 2 Sheets-Sheet l Feb.11, 1930. IUNGA1,746,786

CARBURETOR Filed July 11, 1923 2 Sheets-Sheet 2 Patented Feb. 11, 1930UNITED. STATES PATENT OFFICE "'roRBJonn-Lnvemor xoxomo, INDIANA,ASSIGNOR, BY mnsnn ASSIGNMENTS, r PHIL snnmmm, or CHICAGO, ILLINOIS Vcannunn'ron Application filed July 11,

. One object ofthe invention is to provide a carburetor construction forthe internal combustion motor of anautomobile or the like having arelatively high velocity flow 1n 5 the mixing tube when the motor withwhich the carburetor is associated is idling or when the automobile'isbeing driven at a very low speed, for the adequate and effectivemechanical subdivision of the entrained fuel and its thoroughintermixing with the air with 'which it is associated.

Also, it is essential to keep the suction at high speeds of theautomobile at a comparativelylow point, or, stated somewhat otherwise,it is desirable to avoid an excessive tion, unlesssome special provisionis made,

' an excessive or-undue suction would be pres ent at a high speed of theengine, with a resultant reduction of engine compression and aconsequent lessening of maximum power.

It would be preferable, if it were possible of accomplishment, tomaintain a substantially constant or practically unvarying velocity inthe mixing chamber of the carburetor at all engine speeds, and in mydevice this is substantiall efi'ected.

To attain'the a ove specified object, the new and improved carburetorhas a mixing tube of comparatively small cross section to assure therequired high velocity flow therethrough, anda supplemental, air-inlet,constant-weight valve is employed, which does not start or begin to openuntil the suction has reached a predetermined amount, for example, thatcorresponding to approximately a fourteen-inch water column. Thisexplains how the high initial velocity is secured. When the suctiontends to increase, such valve opens and, by the admission of air, keepsthe suction down, which otherwise would become excessive, such valvebeing em ployed for the purpose of maintaining an air velocity in themixing chamber which varies as little as possible.

Obviously the fuel ought to be introduced 50 in proportion to the amountof air passing 1923. Serial 1%. s5o,744.-

through the carburetor, and to do this, or to govern this action, theextent of travel of the valve is employed as an adjusting means toeffect the correct ratio of fuel to air.

Although the suction in the mixing tube is more or less constant, thesuction at the mouth of the fuel orifice is not uniform, but variessubstantially as the square of the air velocity through the carburetor.

Under normal idling conditions, the suction in the starting-well, thatis, the chamber or compartment with which the fuel discharge openingsconnect and into which the fuel is delivered, is less than thatcorrespond ing to one-half inch water column, and hence only the lowerfuel openin is operative, and proper idling can be rea ily and easilysecured by adjustment of the needle-valve controlling the low-speedlower fuel nozzle.-

The use of the lower'fuel nozzle alone will give a progressively leanermixture as the engine speeds up, and to compensate for thisunsatisfactory condition a second fuel passage or-discharge is neededwhich will supply a progressively rich-er mixture.

To accomplish this result, the first fuel nozzle is located below thefuel level of the carburetor supply and the second. nozzle is positionedabove such level.

To modify .the fuel ratio curve when the two nozzles are operative, Iemploy a tapered metering cone mounted on the con st-ant-Weight valuereferred to, such cone higher opening is adjusted for high speed.

The first jet mixture being too lean for high speed, the second jetmixture gradually compensates or progressively enriches the mixture,which becomes leaner step by step were the first jet used alone. i

A further obj cct of the invention is to provide a carburetor which willpermit the motor ratio of fuel to air under all to start easily underall conditions of service, and to the accomplishment of this result thestarting-well is filled by gravity just as soon as'the engine isstopped, and hence a rich mixture is automatically delivered totheengine each time it is started.

Another aim of the invention is to so construct the carburetor thatquick acceleration of the automobile may be had, which means that thegaseous mixture should be temporarily enriched to secure such desiredacceleration.

Other objects of the invention are the securing of a maximum economy bya carburetor which is simple in structure, which is easily regulated,which does not get out of adjustment, and which may be made atrelatively' small cost.

The carburetor is economical in action because there are perfect meansfor almost exact compensation, thus maintaining a proper conditions.

This in the new carburetor is accomplished by the use of an unvaryingweight controlling the action of the air-valve, instead ofdependinggupon' the action of a varying spring,

and a definitely designed metering-cone,

- which can be constructe with exact predetermined characteristicsimpossible in springs.

In order that those skilled in this art may have a full and completeunderstanding of the invention and its structural and funct-ionaladvantages,

I have illustrated a preferred embodiment of the invention in theaccompan ing drawin s, forming apart of this speci cation, and troughout the several views of which like reference characters'refer tothe same parts.

In these drawings,'

Fig. 1 is a substantially-central, vertical, lon 'tudinal sectionthrough the im roved car uretor, with certain portions roken away tomore clearly illustrate the construction; I

Fig. 2 represents the bearin for the sliding hollow stem or mixing tubeof the valve, such bearing being shown in section;

ig. 3 is a vertical cross section on line 33 of Fig. 1;

Fig. 4 is a horizontal section on the irregular line 4-4 of Fig. 1;

Figs. 5 and 6 illustrate the ball-valve construction with the ball indifferent cross sections; and

Fig. 7 is an enlarged plan view of the valve seat member with which theball co-operates.

Referring to these drawings, it will be seen that the eludes the usualfloat chamber 10, housing the liquid fuel supply and accommodating thecustomary float 11 operating a sliding valve- 12 through the leverconnections 13, 13 to control the inlet passage 14 whereby to maintain asubstantially-constant liquid-fuel level 15 in the chamber, the passageor connection improved and novel carburetor in- F 14 being fitted withthe common screen 16 and with a pipe connection 17 to the main source offuel supply.

This float chamber 10 has the familiar removable cover 18 normallydemountably held in position by a leaf spring 19 which may be rocked byits handle 21, when desired, into inoperative position, thus permittingthe removal of the cover. All of this is of the Well known and familiarconstruction. i

The carburetor includes also a chamber or compartment 22 (Fig. 1), thelower internal portion of which is equipped with screw threads coact'ingwith the threads of a plug member 23 (Figs. 1 and 2) having an angularhead 24 by which it may be turned and a cireasily adjusted orcontrolled.

In the present structure, the opening 27 is approximately one quarter ofan inch below the fuel level in the compartment 10, whereas the opening28 is about one-half inch above such designated level.

As shown, the notched or fluted heads 3 of the two needle-valvesspecified are in cooperative .relation with a pair of springpressedlocking or holding pins 35, 35, de-

signed to prevent unintentional turning of the valves, yet permittingtheir ready manual manipulation for securing the desired or requiredadjustments.

The bearing member 23 has openings 36 through its sides to its hollowinterior, and its upright, central, cylindrical bearing 37 slidinglyaccommodates the hollow stem or shank 38 of a round valve 39 on its topend designed and adapted to coact with an annular valve-port 41 in ahorizontal division or partition wall 42 of the carburetor and a triflelarger than the valve, all as is fully shown in Fig. 1. When in itslowermost position substantially closing the port 41, valve 39 issupported by a shoulder 50 on its stem resting on the top of the element23, as is depicted in Below the bearing membe '23, the carburetor has acylindrical. dash-pot chamber 43 closed at its lower end by a threadedplug or closure 44 and containing a rcciprocatory plunger or piston 45fixedly secured on the lower. solid endof the valve-shank 38.

Such plunger or piston has a small bleedcr f or, relief port46 extendedvertically there Y through, and inaddition it is supplied with aplurality of larger ports 47 extended through it, the upper ends of thelatter ports being normally closed and covered by a centrally "apertureddisk 48 having limited play or u movementon the valve-stembetween thepis ton and a shoulder 49 on the stem.

There'is sufficient leakage so that the dashpot chamber 43 is at alltimes filled withthe liquid fuel, whereby the upward or ascend- Zing.movements of the valve 39 are retarded or restrained. by the dash-potmechanism, whereas its descent is comparatively free and round,a1r-adm1ss1on aperture 51 through I g which the valvestem or shankextends, such hole or port 51 affording means'for a down- 1 swardpassage therethrough of more or less of I theair'which flows throughthecarburetor.

I In order that such port or opening 51 may be controlled or openedlmoreor less as circumstances require, the hollow valve shank or :stem 38 isfitted or supplied with a meteringcone 52, which closes the port in moreor less degree-as the valve 39 rises under the suction to which itissubmitted, thus increasing the fsuctionin thechamber-22 at the twodifferent-level fuelopenings.

The upright cylindrical passage, or mixing conduit, 53, in. thevalve-stem 38 (closed at its lower end) has side openings 54therethrough connecting such internal bore or assage with an innerannular chamber 55 nside of the middle portion of the element 23,.andwith which the openings 36 connect,

sothat the chamber 22 is in direct communication with theverticalpassage 53 inside of the valve-stem.

Internally, the top of the round valve member39 has a series of radialgrooves 56 and 57,1(Fig. 7), thealternate grooves 56 being somewhatdeeper than the remaining or companion alternate grooves 57.

At the center of its top, this valve member has a semi-sphericalcavityor recess 58 ac-- commodating a ball-valve 59, and when this ballisresting on its seat in such cavity the lower parts orends of the taperedgrooves 56 arejopen, at which time the other grooves 57 are closed bythe ball.

When the suction is suflicient to raise the ball, then, at leasttemporarily, all of the radial grooves or'passages are open.

' A rou d, centrally-recessed cover-plate 61 fastened'over and to themember 39 by screws 62, 62, leaving an annular space 63 between the twoparts 39 and 61, connecting the outer or upper ends of all of thegrooves 56 and 57, whereby the contents of the latter the engine, siredfor its choking effect until after the may be delivered or dischargedout laterally through this horizontal, shallow, annular gap.

The inner or under surface of the top valve-member 61 is centrallyrecessed at to receive a portion of the ball-valve, such cavity being ofa suflicient size to permit the rise of the ball-valve as describedabove.

The cylindrical, upright passage 53 in the stem of thej valve whichconnects with the series of radial grooves56 and 57 in the top of thevalve-member constitutes a mixing tube, the suction through ofadjustment or variation by the movements of the ball'valve controllingthe grooves 57 The part 64 of the carburetor represents the means forfastening it to the intake-manifold which is capable of the motor, andinternally this portion of the structure is equipped with the usualthrottle-valve 65, beneath which is thechamber 66 above the valve 39 andforming a portion of the general passage through the carburetor.

Thetpart 67 of the device is for the admission 0 the outside air to thatpart of the carburetor above the chamber 22 and beneath the valve 39,and'this part of the appliance is fitted with a choke-valve 68, which,however, need notbe manipulated for starting but is sometimes requiredor demotor becomes somewhat heated up.

It will be observed from an understandingof this construction that Ihave removed both fuel orifices or nozzles out ofthe mixing tube 53, andwhereas a high and nearly constant suction is maintained in the latter,a variable suction at the fuel jets is brought about corresponding tothe required feed of fuel under varying conditions. i

The operation of this carburetor takes place practically as follows:

When the engine is idling, the constantweight valve 39 almost closes thevalve port 41 and the ball-valve 59 is down, closing the grooves 57, butnot closing the deeper grooves 56. Mostof the air entering thecarburetor through the connection 67 flows down through the annular port51 and past the two fuel openings 28 and 27, but inasmuch as thesuction'at this time is insufficient to cause a delivery of fuel throughthe upper opening 28, the air receives all of its charge of fuel throughthe lower fuel nozzle or opening 27, and the mixture flows through theports or openings and passages 36, 55, 54, mixing tube 53, grooves 56and gap 63 into the part 66 of the carburetor above the valve 39, fromwhence it passes by the throttlevalve 65 into the motor. 7 i

As the engine speeds up, the valve 39 rises by reason of the increasedsuction, which overcomes the weight of the valve, permitting an amountof supplemental air to pass dino I rcctly through the valve-port 41, andsuch upward travel of the valve-stem 58 carrying the metering-cone 52causes a artial closing of the air port 51, bringing a out a suctionspeed or as the. square of the air Velocity t rough the carburetor,although the suction in the mixing tube' 53 undergoes only slight, ifany, chan e.

Thus the uel is supplied to the air in such proportion as is required tocarburet the shunted air and to maintain the required ratio between fueland air in the explosive, gaseous mixture. The movements of theconstant-weight valve 39 are retarded and the valve prevented fromfluttering by the action of the dashot construction associated with thelower en of its stem.

The metering-cone can be designed to secure the best results desired,and it is to be observed that no springs with their unreliable 'variableexpansion or extension or compression characteristics are employed inconnection with this valve, its weight alone determinin when it will belifted off of its seat a and t e extent'of such movement which istransmitted directly to the metering-cone.

Such constant-weight valve does not start to open until the suctionabove the valve has a reached an equivalent of approximately four teeninches water column, the suction on the inside of the mixing tube53varying comparspeeds of the car.

The high velocit in the mixing tube 53 is required to secure t e properintermixture of air and fuel, articularly when the engine is idlin andin eneral the higher the velocity t iebetter t e mixing of the elementsof the gaseous mixture.

The metering-cone represents the final adjusting means to secure thecorrect fuel curve that is to say, to produce the correct fuel ratio toair, which ought to remain substantially constant except that a richermixture is needed when the engine ishtraveling slowly or idling and whenaccelerating.

The combined action of the constant-weight air valve 39, the weight ofwhich corresponds to about fourteen inches Water-column suction, and themetering-cone 52, which varies the opening of port 51, produces the sameresult as an ideal spring with variable tension for the differentdegrees of compression of the spring, and the value of this improvedconstruction resides in the fact that whereas mechanically the springcan not be controlled exactly in its action, the shape of the cone canbe made approximatel that which is desired, and consequently t e actionof the metering-cone can be predetermined and exactly secured.

It will be seen that as soon as the engine or motor is stopped, theso-called starting-well in the lower portion of chamber 22 will befilled with fuel by reason ofthe connection 27 with the float chamber,and conse uently as soon as the en ine is'started, a ric v mixture willtemporari y be delivered to the engine, facilitating its startingaction. Under quick acceleration, of course, the upwardmovement of thevalve 39 is retarded by the dash-pot mechanism, but the ball-valve 29 isfree to-rise under such conditions, temporarily or momentarily modifyingthe suction at the fuel jets, whereby a rich mixture is delivered to theengine to produce the required acceleration until the main valve 39itself can respond.

It is to be understood that the invention is not'limited and restrictedto the precise and exact details herein presented, and is susceptible ofa variet of embodiments, this particular carburetor eing subject tochange in its various structural elements within comparatively widelatitudes without departure from the substance and essence of theinvention and without the sacrifice of any of its material benefits andadvantages.

I claim:

1. In a carburetor having first and second air-inlet ports, thecombination of a vertically-slidable valve co-operating with said firstair-inlet port and ada ted tobe raised to open said port by the suctionpresent in the carburetor, said valve having an upright tuthrough whichterminates in a discharge orifice in a first chamber above said firstair-,

inlet port, means to retard the opening action of said valve, saidsecond air-inlet port communicating with a second chamber having meansfor the delivery of fuel thereto and connected to said passage throughsaid tubular stem, a cone on said stem coacting with said secondair-inlet port, a throttle-valve for the carburetor above said firstchamber, and a valve controlling the passage through said stem freelymovable under the action 0 the suction in said first chamber.

2. In a carburetor having first and second air-inlet ports, thecombination of a vertically-slidable valve co-operating with said firstair-inlet port and adapted to be raised to open said port by the suctionpresent in the carburetor, said valve having an upright tubular stemmovable therewith, the passage through which terminates in a dischargeorifice in a first chamber above said first air-inlet port, means toretard the opening action of said valve. said second air-inlet portcommunicating with a second chamber having means for the delivery offuel thereto and connected to said passage through said tubular stem, athrottle-valve for the carburetor above said first chamber, and a valvecontrolling the passage through said stem freely 'movable under theaction of the suction in said first chamber.

3. In a carburetor having first and second air-inlet ports, thecombination of a constant-Weight vertically-slidable valve co-op cratingwith said first air-inlet port and adapted to be raised to open saidport by the suction present in the carburetor, said valve having anupright tubular stem movable therewith, the passage through whichterminates in a discharge orifice at the top of the valve, means toretard the opening action of said valve, said second air-inlet portcommunicating with a chamber having means for the delivery of fuelthereto and connected to the passage through said tubular stem, athrottle-valve for the carburetor above said valve, and a valvecontrolling the opening of said orifice freely movable under the actionof the suction in the carburetor.

4. In a carburetor having first and second air-inlet ports, thecombination of a vertically-slidable valve cooperating with said firstair-inlet port and adapted to be raised to open said port by the suctionpresent in the carburetor, said valve having an upright tubular stemmovable therewith, the passage through which terminates in a, dischargeorifice in a first chamber above said first airinlet port, means toretard the opening action of said valve, said second air-inlet portcommunicating With the top of said second chamher having means for thedelivery of fuel into the loweriportion thereof and connected to saidpassage through said tubular stem, a cone valve on said stem coactingWith said second air-inlet port,a. throttle-valve for the carburetorabove said first chamber, and a valve controlling the pasasge throughsaid stem freely movable under the action of the suction in said firstchamber.

In Witness whereof I have hereunto set my hand.

TORBJORN LINGA.

